Various means have in the past been used to lock the reciprocable plunger of a hand-help pump dispenser when not in use. Usually the plunger and an adjoining member are relatively rotated between operative and inoperative positions of the plunger, as for example shown in U.S. Pat. Nos. 3,797,705 and 3,827,605, commonly owned herewith. Such relative rotation may move ribs and grooves between the parts into and out of alignment with one another so as to respectively permit reciprocation of the plunger and to lock the plunger in its raised position. U.S. Pat. Nos. 3,590,691; 3,422,996 and 3,489,322 illustrate such a locking means. However, it has been found that the ribs and grooves have a tendency to inadvertently align themselves especially if the dispenser is tampered with or dropped thereby defeating the purpose for which the locked dispenser is intended, i.e., a child-resistant and safety pump dispenser. When in the hands of children, the rotatable parts of these pump dispensers are capable of being easily manipulated to a point where the ribs and grooves will eventually become aligned into an operable position of the plunger. Moreover, the container closure member utilized for mounting the pump dispenser to a container is typically, in prior art designs, threadedly engageable with the container so as to be easily manipulated for removal. These and other aspects of the prior art arrangements detract from their effectiveness as a safety or child-resistant dispenser actuator.